12.1-12.2 Gas Notes
1. Choose True or False
T F Gases experience no intermolecular forces
T F Gases are fluids
T F Gases have high densities
T F Gases are not compressible
T F Gases completely fill a container
T F Gases are constantly moving at high speeds
T F Collisions of gas molecules is what causes air pressure
T F atm, bar, mmHg, Pa, psi, and torr are all units of Pressure
T F Volume, moles, pressure, and temperature are all measurable properties of gases
2. If two variables have a direct relationship, what does this
mean?________________________________________________________________________________________________
3. If two variables have an indirect relationship, what does this
mean?________________________________________________________________________________________________
4. Imagine a helium balloon you received for your birthday.
What will happen to the balloon if you put it inside a refrigerator?____________________________
What will happen to the balloon if you squeeze the balloon?___________________________________
What will happen to the balloon if you put the balloon outside on a hot
day?_________________________________________________
If the balloon has a volume of 22.4L, how many moles of has would be inside the
balloon?___________________________ Number of molecules?________________________________________
P
T
V
Pressure-Volume Relationship (Temperature remains constant) (squeeze a balloon)
A sample of oxygen gas has a volume of 150.0 mL at a
pressure of 0.947 atm. What will the volume of the gas be
at a pressure of 1.000 atm if the temperature remains
constant? (142 mL)
Temperature-Volume Relationship (Pressure remains constant) (heat/cool a balloon)
Helium gas in a balloon occupies 2.5L at 300.0K. The
balloon is dipped into liquid nitrogen that is at a
temperature of 80.0K. What will the volume of the helium
in the balloon at the lower temperature be? (0.67 L)
Temperature-Pressure Relationship (Volume remains constant) (heat/cool a steel tire)
At 1220C the pressure of a sample of nitrogen is 1.07 atm.
What will the pressure be at 2050C, assuming constant
volume? (1.29 atm)
The Ideal Gas Law
1. How many moles of air molecules are contained in a 2.00 L flask at 98.8 kPa and 25.00C? (.0797 mol)
2. Calculate the pressure exerted by 43 mol of nitrogen in a 65L cylinder. (1500 kPa)
3. What is the volume of 4.35 moles of a gas at a pressure of 85.6 kPa and 26.00C? (126L)
4. How many moles of gases are contained in a can with a volume of 555mL and a pressure of 600.0
kPa at 200C? (0.137 mol)